Biological sciences

Research was conducted to examine the chemotaxis of pathogenic Vibrio strains towards mucus surfaces of gilt-head sea bream Sparus aurata L and to stuy the influence of salinity and temperature on the process. Twenty-two strains of Vibrio anguillarum and Vibrio alginolyticus were isolated from diseased gilt-head sea bream and their abilities to assay were determined following the preparation of raw skin, gill and intestinal mucus. Results indicate that the mucus surfaces are potential portal entries in the fish for V anguillarum and V alginolyticus.

The adhesive kinetics of Vibrio strains isolated from diseased gil-head sea bream to superficial skin mucus was investigated by adhesive assay and spectroscopy. Data indicated saturation kinetics for V. anguillarum-like strains, whereas V. alginolyticus showed a proportional adsorption kinetics. Mucus did not have an effect on the adhesive ability of the pathogenic microorganisms, suggesting that there is no relationship between adhesive capability for skin mucus and virulence.

A long-term epidemiological study of cryptosporidium molnari in aquacultured European sea bass (ESB) and gilthead sea bream (GSB) was performed in different types of facilities on the Atlantic, Cantabric, and Mediterranean. It is found that recirculation systems and fish cannibalism can contribute to oocyst concentration and dispersion in aquaculture facilities.